Variation in the serum bilirubin levels in newborns according to gender and seasonal changes

Abstract

Introduction: Bilirubin is a substance that is produced during the process of hemolysis. Gender influences on neonatal illnesses and outcomes have remained a topic of debate and investigation. Empirical neonatological experience suggests that prevalence and degree of neonatal jaundice might be dependent on seasonal variation also. The aim of our study is to interpret the bilirubin levels in newborns according to gender and seasonal variation. Materials and Methods: The study was done from October 2012 to July of 2013 (differentiated by seasonal variation). A total of 1000 jaundiced newborn (500 of each sex diagnosed clinically and divided equally in summer and winter season) were studied to assess the total, direct and indirect serum bilirubin levels using colorimetry. Results: Out of total 1676 deliveries (439 were caesarean, 13 were assisted and rest were normal) during winter season and 1475 deliveries (399 were Cesarean, 14 were assisted and rest were normal) during summer season, 500 male newborn and 500 female newborn were analysed, divided equally in both seasons. Serum bilirubin was higher in males in summers and mainly comprised unconjugated bilirubin while direct bilirubin was higher in females in winters. Raised indirect bilirubin was more common in males born in summer than those born in winters (P = 041). In winters raised direct bilirubin was more common in females as compared to males (P = 0.019). Among female neonates total and indirect bilirubin was significantly raised in those born in summers (P = < 0.001 and <0.001, respectively) while direct was raised in those born in winters (P = 0.003). Conclusion: Physiological and pathologic phenomena associated with male gender must be integrated in the frame of understanding of both susceptibility and protection of the male newborn which has not been available for adequate investigation in the past. The higher temperature during the summer, with a greater influence of higher breastfeeding cause more severe hyperbilirubinemia.